These are an interesting variation on geocaching. There are quite a few for the U.S. Many appear constructed by tourist bureaus/groups to promote tourism in the area. They look really interesting and there is one for Milwaukee!

Article dated February 2014 before the Hachette/Amazon dispute erupted. Provides some background on the Amazon/publishing situation and asks questions about things like, is a low price always in the best interest of consumers? Provides a lot of context for both sides.

Description of the Hachette/Amazon dispute. Provides a lot of history and context for publishing (traditional) and ebooks and Amazon's relation with both over time. This is a long article that outlines the history that leads up to the current publisher/Amazon relationship. Dated December 2014. The current Apple ebooks lawsuit is not yet decided but that's another chapter in this story.